Title: Coupled Effect of Lightweight Aggregate and Shrinkage Mitigation Strategies on Performance of SCC

Author(s): Kamal Khayat

Publication: Web Session

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Date: 10/25/2020

Abstract:
The presentation will discuss testing undertaken to determine the effect of the lightweight coarse aggregate type (expanded shale or slate) and substitution rate of coarse aggregate (0, 25%, 35%, and 50%) and lightweight sand (0 and 20) on key engineering properties and durability of self-consolidating concrete (SCC) designated for repair applications. Test parameters included the dosage rate of shrinkage-reducing admixture and expansive agent. Test results indicated that the investigated mixtures can exhibit good frost durability with durability factor equal to or greater than 90%, regardless of the substitution rate of lightweight aggregate. The incorporation of 20% lightweight sand and 25% lightweight coarse aggregate led to significant reduction in autogenous and drying shrinkage with limited drop in mechanical properties and durability. This indicates that the contribution of internal curing to reduce autogenous and drying shrinkage is greater than the increase in porosity and decrease in stiffness resulting from the addition of such porous material.